Medical suctioning bacteria valve and related method

ABSTRACT

A valve and method for preventing backflow of bacteria and other unhealthy substances in a medical suctioning apparatus. The valve defines a chamber and has an outlet and an opposed inlet. The valve provides a tortuous path that effectively limits backflow of bacteria and other unhealthy substances. The valve further includes a diffuser proximate the outlet to direct backflowing fluids to travel the full length of the tortuous path. The valve is used between a medical suctioning unit and a patient-contacting part such as an ejector, evacuator, or yankauer.

This is a divisional of application Ser. No. 08/618,524, filed Mar. 19,1996 now U.S. Pat. No. 5,728,078.

BACKGROUND OF THE INVENTION

The present invention relates to a valve and method for preventing thebackflow of body fluids and bacteria through medical suctioningequipment.

Medical centers, hospitals, dental practices, and other medicaloperations commonly use suctioning equipment to remove body fluids, suchas saliva or blood, during medical procedures. These body fluids cancarry or become contaminated with bacteria and other unhealthysubstances. Consequently, it is important to prevent the body fluids,bacteria, and other unhealthy substances from backflowing or moving in areverse direction into any patient. This can be problematic sincesubstances such as bacteria will travel along surfaces without theassistance of a fluid carrier. For example, even if the part of themedical suctioning apparatus that contacts a patient is replaced witheach new patient, bacteria can travel in a reverse direction through thenew part and thus still cause a problem. Therefore, particularly in viewof public concern over communicable diseases and diseases that can betransmitted by body fluids, it is important that maximum protectionagainst undesired backflow and/or movement of bacteria be provided.

U.S. Pat. No. 4,083,706 to Wiley discloses a sterile trap accessoryinserted between a suctioning conduit and an aspirator. The trapaccessory includes a filter for catching debris and a tubular sectionthat protrudes into the trap toward the filter. The filter effectivelycaptures debris for later viewing by a medical worker or doctor; howeverin doing so large amounts of debris are held in the trap accessory, thuspotentially increasing the risk of bacteria movement in a reversedirection. Further, the surfaces between the filter and the inlet to thetrap accessory permit backflow of bacteria.

SUMMARY OF THE INVENTION

The aforementioned problems are overcome in the apparatus of the presentinvention wherein a backflow valve includes a tortuous surface paththrough the valve that all fluids and bacteria must follow in attemptingto move between the outlet and the inlet. Further, all fluids thatbackflow through the outlet are forced by diffusion or deflection tofollow the full tortuous path.

In the associated method, fluid and bacteria backflow is prevented byinserting into the section line a backflow to valve provide a tortuoussurface path between the valve outlet and valve inlet. As disclosed, thevalve includes a peripheral wall forming a portion of the tortuous path;and the method includes the step of diffusing or directing backflowingliquid toward the peripheral wall so that it must follow the full lengthof the path.

Fluids are suctioned through the valve from the inlet to the outlet, bydrawing a vacuum through the valve but bacteria cannot readily backflowthrough the valve due to the tortuous path and the diffusion of anybackflowing fluid.

These and other objects, advantages, and features of the presentinvention will be more readily appreciated and further understood byreference to the detailed description of the embodiment and thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of a first embodiment antibacterial valvewith the outer housing partially broken away to illustrate the interior;

FIG. 2 is an exploded perspective view of the valve;

FIG. 3 is a side view of the valve;

FIG. 4 is an exploded side view of the valve;

FIG. 5 is an enlarged schematic illustration of the valve showing thetortuous surface path which prevents backflow of bacteria through thevalve;

FIG. 6 is a side view of an assembly including a second embodiment valvereleasably connected to a saliva ejector;

FIG. 7 is a perspective of view of the assembly shown in FIG. 6;

FIG. 8 is an exploded side view of the assembly shown in FIG. 6;

FIG. 9 is a side view of a third embodiment valve releasably connectedto a disposable oral evacuator;

FIG. 10 is an exploded side view of the assembly shown in FIG. 9;

FIG. 11 is a side view of a fourth embodiment valve releasably connectedto a disposable medical suction yankauer;

FIG. 12 is an exploded side view of the assembly shown in FIG. 11;

FIG. 13 is an exploded view of a fifth embodiment valve including anadaptor for converting the valve for use with either an ejector or anevacuator;

FIG. 14 is a partially exploded side view of the valve shown in FIG. 13,the adapter tip being shown as exploded away but as being ready forattachment to the valve;

FIG. 15 is a side view of the assembly shown in FIG. 13;

FIG. 16 is a side view of the valve shown in FIG. 13 connected to anevacuator, the adapter tip having been removed;

FIG. 17 is a fragmentary sectional view of a sixth embodiment valveincluding an insert including a ring-shaped fin;

FIG. 18 is a side view of an insert for a seventh embodiment valveincluding a pair of ring-shaped fins;

FIG. 19 is a side view of an eighth embodiment valve connected to adisposable oral evacuator;

FIG. 20 is an exploded side view of the assembly shown in FIG. 19;

FIG. 21 is a side view of a ninth embodiment valve connected to adisposal oral evacuator;

FIG. 22 is an exploded perspective view of the assembly shown in FIG.21;

FIG. 23 is a perspective view of the valve shown in FIG. 21 with thehousing partially broken away to illustrate the interior of the valve;

FIG. 24 is a side view of a tenth embodiment valve connected at one endto a disposable connecting tube and yankauer and at the other end to amedical suctioning unit;

FIG. 25 is an exploded side view of the valve shown in FIG. 24;

FIG. 26 is a side view of an eleventh embodiment valve; and

FIG. 27 is an exploded side view of the valve shown in FIG. 26.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An antibacterial valve 30 (FIGS. 1-4) embodying the present inventionincludes a casing 32 and a tortuous-path-forming member 34 located incasing 32. Casing 32 includes inner surfaces defining a chamber 36, andan inlet 38 and an outlet 40 located at opposite ends of chamber 36.Valve 30 is particularly constructed to allow flow of body fluidsthrough valve 30 from inlet 38 to outlet 40, but is constructed toprovide a tortuous path 42 (FIG. 5) to inhibit undesired movement and/orbackflow of bacteria and other unhealthy substances from outlet 40 toinlet 38. The "tortuous path" method of preventing backflow of bacteriais based on Pasteur's theory of curved paths for protection from germs.It is contemplated that these valves can be made from disposable orautoclavable materials such as polymeric materials.

Valve 30 (FIG. 4) is a two-piece assembly including a first member 50and a second member 52 configured to be press fit to first member 50 tofrictionally engage and form a leak-free joint with first member 50.First member 50 is tubular and includes the outlet 40, a cylindricallyshaped wall 56 of larger diameter than outlet 40, and a frustoconicallyshaped section 58 connecting outlet 40 and cylindrically shaped wall 56.Second member 52 includes the inlet 38 and a frustoconically shapedsection 62 extending from inlet 38. The edge of frustoconically shapedsection 62 is configured to matably engage the end of cylindricallyshaped wall 56. In particular, the end of frustoconically shaped section62 includes a ring 64 configured to press-fittingly engage the inside ofthe end of cylindrically shaped wall 56, and further includes anabutting ring 66 configured to engage the end of cylindrically shapedwall 56 to prevent over-insertion of second member 52 into first member50. Second member 52 further includes a tubular protruding section 68that extends from inlet 38 into chamber 36. Tubular protruding section68 includes an inwardly tapered elongated wall section 70 having areversely oriented ring-shaped fin 72 on its end that protrudes radiallyinto chamber 36. Ring-shaped fin 72 is preferably oriented at an acuteangle to longitudinal centerline 74 and is reversely formed andarcuately shaped so that it extends backwardly toward inlet 38, althoughit is noted that the angle and shape of ring-shaped fin 72 can be variedfor optimal results in specific applications.

When first and second members 50 and 52 are assembled, casing 32 isdefined by cylindrically shaped wall 56, frustoconically shaped section58, and frustoconically shaped section 62. Tortuous path forming member34 is defined by tubular protruding section 68 including fin 72. Asshown in FIG. 5, the inner surfaces of casing 36 and the surfaces ofelongated wall section 70 and fin 72 advantageously form tortuous path42. The tortuous path 42 prevents undesired movement of bacteria in acounterflow direction through valve 30 in large part because bacteriatends to grow or move along surfaces, or tends to otherwise move inlinear paths when moving without the assistance of a flowing carrierfluid.

As illustrated in FIGS. 1-4, vacuum release vents 73 extend through thefirst member 50 proximate the end opposite the outlet 40. Each vent is"pin size," meaning that it is large enough to permit air to flow in butnot large enough to permit liquid, such as saliva or other body fluidsto flow out. In the presently preferred embodiment, four such vents 73are spaced equidistantly around the circumference of the member 50. Thevents 73 prevent liquids from becoming entrapped or stagnant with thespace surrounding the protruding section 68. Air flowing into the valve30 through the vents 73 enables fluids to travel along the tortuous path42 toward the outlet 40.

Advantageously, an antibacterial valve such as valve 30 can be used witha variety of different medical suctioning devices. Further, the valvecan be formed in different sizes, shapes and configurations to optimizeflow-through characteristics and to facilitate assembly of the valve.The following discussion discloses a variety of valve configurations. Toreduce repetitive discussion, comparable items and features in thefollowing discussion are labeled with identical numbers used for valve30, but with the addition of letters "a," "b," "c," and so forth.

In FIGS. 6 and 7, a valve 30a is shown attached to an ejector 76a suchas is commonly used to remove saliva from a patient's mouth. Ejector 76aincludes a slotted ejector tip 78a, an elongated deformable tubularstraw 80a, and a releasably engageable connector 82a configured totelescopingly and frictionally engage inlet 38a on valve 30a. FIG. 8shows casing 32a exploded away from ejector 76a, but aligned forconnection thereto. Valve 30a includes a one-piece casing 32a having anenlarged mid-section 56a, an inlet 38a, and an outlet 40a.Frustoconically shaped sections 58a and 62a connect inlet 38a and outlet40a to mid-section 56a, respectively. A tubular second piece or insert68a is attached to and extends from connector 82a of ejector 76a. Insert68a includes an elongated wall section 70a including a bulbous section73a for scalingly engaging the inside of inlet 38a. Bulbous section 73afurther has a diameter chosen to scalingly engage the outside ofconnector 82a. A ring-shaped fin 72a is located on the end of elongatedwall section 70a. Ring-shaped fin 72a is configured to telescope intochamber 36a through inlet 38a. A tortuous path is thus defined along theinner surfaces of valve 30a, which tortuous path prevents backflow ofbacteria. It is noted that casing 32a is a one-piece molding made, forexample, by blow molding or roto-molding. However, casing 32a could alsobe constructed from a pair of injection molded opposing halves (notspecifically shown) which mate along a plane that extends parallel andthrough centerline 74a of chamber 36a.

In FIGS. 9 and 10, a valve 30b is shown attached to an evacuator 90b.Evacuators 90b are commonly used in dentistry practice to selectivelyremove saliva from a patient's mouth. Evacuator 90b has a largerdiameter than an ejector such as ejector 76a to facilitate grasping ofthe evacuator 90b. Evacuator 90b includes a tubular straw 92b includingan angled suction end 94b. Straw 92b includes a second end 96bconfigured to telescopingly press-fittingly engage the inside of inlet38b. Alternatively, it is contemplated that evacuator end 96b couldengage an outside of inlet 38b. Notably, valve 30b includes members 50band 52b that are comparable to members 50 and 52 of valve 30, althoughmembers 50b and 52b have different proportions as needed for optimalflow-through characteristics when connected to evacuator end 96b.

FIGS. 11 and 12 show a valve 30c attached to a yankauer 100c. Yankauer100c includes a first end 102c configured for suctioning blood orrelated matter, a tubular straw 104c extending from end 102c, and asecond end 106c on straw 104c configured to telescopingly frictionallypress-fit onto inlet 38c of valve 30c. Valve outlet 40c includes astepped outer surface 108c such as for connecting to suction lineshaving different diameters. It is noted that casing 36c is shown asbeing one piece. However, it is contemplated that casing 36c could alsobe a multi-piece assembly such as is noted above in regard to valve 30aor as is noted below in regard to valve 30h.

Another valve 30d (FIGS. 13-15) includes first and second members 50dand 52d, respectively, that can be matably engaged to form a chamber 36dand a tortuous path-forming member 34d. An adaptor 114d is configured tomatably engage the inlet 38d. Specifically, adaptor 114d includes a ring116d having a diameter chosen so that it frictionally sealingly engagesinlet 38d, and an abutting lip 118d for engaging the end of inlet 38d toprevent overtravel of adaptor 114d into inlet 38d. Adaptor 114d furtherdefines a second inlet 38d' having a reduced size compared to inlet 38dso that, for example, an ejector 76d can be attached to second inlet38d'. A frustoconically shaped wall 120d interconnects ring 116d andsecond inlet 38d'. FIG. 16 illustrates use of valve 30d without adaptor114d, valve 30d being connected to an evacuator 90d.

It is contemplated that some applications may require an even moretortuous path than tortuous paths 42 of valve 30 shown in FIG. 5 andvalves 30a through 30d shown in FIGS. 6-16. For this purpose, a valve30e including a separate insert 124e (FIG. 17) is provided. Insert 124eis shaped generally similarly to second member 52, but insert 124e doesnot include a frustoconically shaped section 62. Rather, second insert124e is configured to fit within and frictionally engage the insidesurfaces of casing 32e. More specifically, insert 124e includes tubularprotruding section 68e and ring-shaped fin 72e. A circumferential rib125e on tubular protruding section 68e extends outwardly and isconfigured to engage a depression 126e in cylindrically shaped wall 56eof casing 32e. It is noted that depression 126e can be located anywherein casing 32e, and that multiple depressions 126e can be used to locatemultiple inserts 124e in casing 32e. Tubular protruding section 68efurther includes an end 127e configured to engage the inside surface onthe end of frustoconically shaped section 62e. Casing 32e is constructedof opposing members such as members 50e and 52e due to the largediameter of ring-shaped fin 72e. Notably, more than one insert 124e canbe positioned in casing 32e at a time, thus greatly increasing theeffective length of the tortuous path.

Another insert 129f (FIG. 18) is identical to insert 124e except thatinsert 129f includes a second ring-shaped fin 72f spaced longitudinallyapart from first ring-shaped fin 72f on tubular protruding section 68f.Also, end 127f is formed with orthogonal surfaces. It is contemplatedthat even more than two fins 72f could be located on insert 129f, orthat multiple inserts 124e and/or 129f could be positioned inside ofcasing (32e).

FIGS. 19 and 20 show a valve 30g including members 50g and 52g, and aninsert 124g in combination with an evacuator 90g. Valve 30g includes apair of reversely lipped ring-shaped fins 72g and 72g', fin 72g being onmember 52g and fin 72g' being on insert 124g. Insert 124g furtherincludes cylindrically shaped end 127g configured to securelyfrictionally engage the inside of casing 32g. Notably, a double-finnedinsert as illustrated by insert 129f can be substituted for insert 124g,in which case the valve 30g would define three ring-shaped fins.

In FIGS. 21-23, a valve 30h is illustrated that includes members 50h and52h. Member 52h is three piece and includes a chamber-forming shell130h, a tubular protruding section 132h and a ring-shaped member 134hconfigured to matably engage tubular protruding section 132h.Ring-shaped member 134h includes a ring-shaped fin 72h and a tubular endor stub 136h configured to frictionally engage the end of tubularprotruding section 132h. Notably, it is contemplated that tubularprotruding section 132h can be an integral part of another member suchas an ejector 76h. To assemble member 52h, the tubular protrudingsection 132h is press-fittingly sealingly extended through inlet 38h ofcasing 32h, and tubular stub 136h on ring-shaped member 134h isfrictionally engaged onto tubular protruding section 132h. Valve 30h isthen assembled by press-fittingly or otherwise assembling members 50hand 52h together.

In FIGS. 24-25, a valve 30i generally comparable to valve 30g isattached to medical suction unit 140i at outlet 40i and to a yankauer100i by a disposable flexible tube or hose 141i. Valve 30i includes aninsert 124i having an end 127i with a cylindrically shaped outer surface138i for engaging a recess 140i in cylindrically shaped wall 56i. Aradially extending surface 142i limits insertion of insert 124i intocylindrically shaped wall 56i. Member 52i includes a cylindricallyshaped wall 144i sized to telescopingly slide over insert surface 142iand frictionally securely engage the outer surface of cylindricallyshaped wall 56i. Valve member 52i includes an inlet 38i configured toreceive flexible tube 141i, and valve member 50i includes a steppedoutlet 40i configured to receive a connector 146i on medical suctionunit 140i.

An eleventh embodiment, and currently the preferred embodiment, isillustrated in FIGS. 26-27 and designated 30j. This embodiment of thevalve includes a housing 50j, an inlet insert 52j, and a diffuser 150j.The unique component of this embodiment is the diffuser 150j; thehousing 50j and inlet insert 52j can be any of the constructionsdescribed above.

The housing 50j includes an outlet stem 40j, a frustoconical peripheralwall 56j, and a frustoconical neck 58j interconnecting the foregoing.These three portions are axially aligned with one another and arefabricated as a single piece.

The inlet insert 52j includes an inlet stem 38j, a shoulder 62j, and atubular extension 68j. These three portion are axially aligned with oneanother and are fabricated as a single piece. The shoulder 62j isconfigured to friction fit or snap fit into the housing 50j. The inletextension extends into the chamber 36j and terminates in an inlet mouth71j. A peripheral circumferential rib 72j on the extension 68j surroundsthe inlet mouth 71j.

The tortuous surface path, as in the other devices includes a) theentire interior surface of the housing 50j, b) the interior surface ofthe shoulder 62j, c) the exterior surface of the inlet extension 68j,and the rib 72j. The reverse created by the inlet extension 68j and thesharp edge of the rib 72j are particularly effective in contributing tothe tortuous path.

The diffuser 150j includes a central portion 152j and a peripheralportion surrounding the central portion. The diffuser is shown in twopositions in FIG. 27--a plan view and a side view illustrating thediffuser for insertion into the housing 50j. The central portion isunapertured. The peripheral portion is, in essence, apertured byscallops 154j leaving arms 156j. The diffuser is press-fitted orsnap-fitted within the housing 50j proximate the outlet stem 40j and theneck 58j. The arms 156j engage the peripheral wall 56j.

The diameter of the diffuser central portion 152j is larger than theinterior diameter of the outlet stem 40j and larger than the diameter ofthe inlet mouth 71j. Consequently, the diffuser 150j blocks all directlines or paths between the outlet 40j and the inlet 38j. This preventsbackflowing fluid from traveling directly through the chamber from theoutlet to the inlet. Another way of stating the size relationship isthat the cross-sectional area of the central portion is larger than thecross-sectional area of the outlet 40j and is larger than thecross-sectional area of the inlet 38j.

Further, the diffuser 150j directs all backflowing fluid from the outlet40j to the peripheral wall 56j. This ensures that all backflowing fluidsand any bacteria or other contaminants therein will be forced to followthe full length of the tortuous path. This even further reduces thelikelihood that any bacteria will traverse the full length of thetortuous path and enter the inlet 38j;

The above descriptions are those of preferred embodiments of theinvention. Various alterations and changes can be made without departingfrom the spirit and broader aspects of the invention as defined in theclaims, which are to be interpreted in accordance with the principles ofpatent law including the doctrine of equivalents.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A medical suctioningmethod comprising:drawing a vacuum in a line; inserting a valve into theline, the valve being closed with the exception of an inlet and anoutlet, said inlet formed at an end of a tubular extension extendinginto the valve, said inlet surrounded by a continuous circumferentialrib on and extending radially outward from the tubular extension; andproviding a tortuous surface path through the valve between the inletand the outlet, the tortuous path comprising the tubular extension andthe circumferential rib, whereby backflow of body fluids and bacteriathrough the valve is prevented.
 2. A medical suctioning method asdefined in claim 1 wherein the valve has a peripheral wall and whereinsaid method further comprises diffusing fluid backflowing through theoutlet toward the peripheral wall.
 3. A medical suctioning method asdefined in cliam 2 wherein said diffusing step includes diffusing all ofthe liquid that otherwise might backflow in a direct line from theoutlet to the inlet.
 4. A method of suctioning fluids from a bodycomprising:connecting a first line to an inlet of a backflow valve, thebackflow valve including a peripheral wall, said inlet formed at an endof a tubular extension extending into the valve, said inlet surroundedby a continuous circumferential rib on and extending radially outwardfrom the tubular extension; connecting a second line to an outlet of thebackflow valve; drawing a vacuum on the second line, thereby drawing avacuum through the valve and the first line; and providing a tortuoussurface path between the inlet and the outlet, the tortuous pathcomprising the tubular extension and the circumferential rib, wherebybackflow of body fluids and bacteria through the valve is prevented; anddiffusing fluid backflowing through the outlet radially outwardly towardthe peripheral wall.
 5. A method as defined in claim 4 wherein saiddiffusing step comprises diffusing all of the liquid that mightotherwise backflow in a direct line from the outlet to the inlet.
 6. Amethod as defined in claim 4 wherein said providing step includesforming the inlet at the end of a tubular extension extending into thevalve.
 7. A method as defined in claim 6 wherein said providing stepfurther includes forming a circumferential rib on the tubular extensionabout the inlet.